Zinc comes mainly from meat, seafood, shellfish, nuts and seeds – foods that many people don’t eat enough of. Zinc deficiency includes:
• White marks on nails
• Lack of appetite
• Lack of resistance to infection
• Lack of taste for zinc in the zinc tally test. This is where you take 10ml of zinc solution in to your mouth and report what you can taste. If you taste nothing, which 99% of my nutrition clients report – it suggests a zinc deficiency.
Here are, in my opinion, the top 2 reasons we should be eating more zinc containing foods as well as supplementing with 25mg of zinc a day.
We are HCL deficient. Almost 100% of my clients fail the HCL test (HCL article will posted later this week). HCL is made from zinc, chloride, vitamin B1 and B6 and these are essential for HCL production. Zinc is essential to power the enzymes that convert histamine to HCL, and in fact HCL and zinc deficiency my show up in people with allergies. HCL is essential for the whole digestive process, but it is key for extracting minerals out of food. So you see there is a vicious circle you can fall into if you are zinc deficient – you don’t have zinc to make HCL, so you don’t absorb the zinc in your food!
The second reason why zinc is so important is to support male health. Zinc is required to make testosterone and it is also an aromatase inhibitor. Aromatase is an enzyme found in your fat cells that converts testosterone to oestrogen (not good if you are a male). So we have less zinc to make testosterone and the testosterone we do have is converted to oestrogen as we are getting fatter and have more aromatisation. Dr Bob Rakowsky suggests that we at a point in history where there are more infertile males than females and that male birth rates are dropping day by day – yes males are a dying bread!. Even those males that live are turning in to women (have you seen The Only Way is Essex – Harry and Joey Essex – point proven!!).
The 2007 Summit of Environmental Challenges to Reproductive Health and Fertility reported that testosterone levels in males have decreased 1% per year, every year for the last 50 years! That means we have half the testosterone (and arguably half the sperm count) of our grandfathers. This is in large part due to the sea of chemicals and pollution we are surrounded by. But is also due to decline in HCL and not consuming zinc containing foods?
Prasad et al (1996) found that inducing a specific marginal zinc deficiency in normal young men lead to a decrease in serum testosterone. They also found that zinc supplementation to marginally zinc-deficient elderly men increased serum testosterone levels. So this clearly suggests that zinc plays a role in regulating testosterone secretion.
Meat, seafood and shellfish are rich sources of zinc as are nuts and seeds, these foods also contain healthy fats and saturated fats – another reason why people are afraid of eating them. Nutrition professionals and the general population should not be scared of eating these healthy foods, including some saturated fats. Zinc supplements may also be useful if you are zinc deficient, however, zinc supplementation (ZMA supplements for example) to people who eat a zinc sufficient diet (there are not many of these people out there) has been shown to have no effect on serum testosterone levels (Koehler et al 2009).
Judicious use of zinc such as 15-25mg in a multivitamin and mineral is probably the best way to get adequate zinc on top of a healthy diet containing meat, seafood, shellfish and nuts and seeds.